1. Field of the Inventions
The present inventions relate to an engine control device including modes for engine operation during malfunctions, and more specifically, during induction system malfunctions.
2. Description of the Related Art
Conventionally, for example in a small boat, an operation or displacement amount of an operating lever, also referred to as a “torque request device” or a “throttle lever”, by a boat operator is detected by an operation amount detecting sensor. In these types of watercraft an engine control device is typically used to control an electronically controlled throttle valve that adjusts an amount of air supplied to the engine. The throttle valve can be opened or closed by a motor according to a detection value detected by the sensor (for example, see Japanese Patent Publication JP-A-2004-092640). In this publication, the engine control device is disposed on an outboard motor of a small boat, and includes an electronic control throttle valve for controlling the amount of intake air for the engine, a remote control lever for remotely operating an opening of the electronic control throttle valve, and throttle valve control means for controlling the electronic throttle valve according to operational states of the remote control lever.
This engine control device further includes throttle opening abnormality detecting means, and abnormal state intake air control means. When an abnormality occurs in the opening control for the electronic throttle valve and the throttle opening abnormality detecting means detects the abnormality, at least a minimum amount of intake air that is necessary to keep the engine running is supplied to the engine by the abnormal state intake air control means. Thus, the small boat can “limp-home” (return to port) even if an abnormality occurs in the opening control for the electronic control throttle valve.